//part1:C03:ex3.6.cpp 
//used for statement to replace all with 'X'.
#include <iostream>
#include <string>

int main(void)
{
    using namespace std;
    string s;
    cout << "Enter some characters, include space:\n";
    getline(cin, s);    // read one line, '\n' to end.
    for (auto &c : s)
    {
        c = 'X';
    }
    cout << s << endl;
    
    return 0;
}